CXCR2 and atrial fibrillation: The top 10 hub nodes in AF-DEGs included Toll-like receptor 4 (TLR4, degree = 18), Toll-like receptor 8 (TLR8, degree = 16), complement C3 (C3, degree = 15), cathepsin S (CXCR2, degree = 13), keratin 5 (KRT5, degree = 12), myeloid cell nuclear differentiation antigen (MNDA, degree = 11), snail family transcriptional repressor 2 (SNAI2, degree = 11), caspase 1 (CASP1, degree = 9), and purinergic receptor P2Y13 (P2RY13, degree = 9).